Piston-ring



T. G. SAXTON.

v PISTON RING.

APPLICATION FILED APR. 16. 1919.

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1 l I i a i WITNESSES 7 p. l/VI/LA/TOR flay THU/VH5 a. aA/rm/v BV \w mi #6 [I TTOR/IIEYS lli THOMAS G'UNNI STOW, Oh NEW YURK, N.

PIE'IIDUN-RING.

fipecification of Letters Patent.

Patented Dec. h, 31ml...

application filed April 16, 1919. fierial N0. 290,4l34l.

To all whom it may concern:

Be it known that l, THoMAs Gr. @AXTONL caused by the burning of lubricating oil within the combustion chamber, which lubricating oil has leaked past the pistdn into such chamber.

Almost all of the inventions made in connection with the piston-ring art have tended to designs which prevented the leakage of oil past a piston, by means of a piston ring which was provided with some kind of an' interlocking joint through its body.

l have found that the amount of oil leaking past a fairly open joint through the body of the ring, is almost negligible; and by experiment l have discovered thatthe greater amount of leakage, through which carbonization of the cylinder results, occurs due to the fact that the ring fails to completel fill the groove in which it is mounted. bviously, upon a suction stroke of the engine the ring will slide upwardly in the slot, resulting in a certain amount of oil working between its lower face and the bottom wall of the groove. Upon the expelling, or compression, stroke of the piston, the ring will slide downwardly in the groove, unless it is very tight in the same; and upon the charge v becoming ignited, the flame from the explolih sion will work into the small opening between the upper face of the groove and the upper side of the piston ring and carbonization will, consequently, result. lt is to be understood, however, that the greatest amount of carbonization occurs due to oil leaking entirely under the ring and up into the combustion chamber and being burnt during the explosion stroke.

This function is, of course, not so noticeable in new engines, where the grooves hold the piston ring fairly well against sliding motion, but as soon as the slightest wear occurs in the groove, play will result between the two and a hammering action will be set up which will uickly hammer the groove to a Width anyw ere up to of an inch too wide for the ring. Beyond the fact that carbonization will now take place, resulting in the expenditure and spoiling of a great amount of unnecessary lubricating oil, the side walls of the piston groove will become so "mutilated that it becomes necessary to.

retrue such grooves completely and apply to them a substantially larger ring. However, after a certain length of time, this operation must be repeated.

In such rings which have heretofore been designed to overcome the above defects, there have been constructed what are known as two-or-more-part rings, which are extensible in a direction parallel to the longi-' tudinal axis of the piston, as well as at right angles to the same; but great difficulty has been experienced in mounting these rings "in the grooves of a piston and in then inserting such piston within the cylinder, in view of the tendency of the two or more parts of the ring to come apart upon the slightest provocation. Further, these rings have proved impracticable in view of the fact that the action of the rings, when expanded, or directed in a direction parallel to the longitudinal axis of the piston, tended to throw the outermost ring firmly against the inner face of the cylinder, resulting in "a wearing away of the cylinder, instead of having the outer ring remain constantly in engagement with the inner face of the cylinder under all sizes of grooves and under all strokes of the piston.

My invention aims to overcome all of the aforementioned defects by providing a two-part ring in which the inner part of the I ring is formed of a highly expansible material, and such inner part is encircled by an outer ring of less expansible material. The two parts of the ring cooperate with one another to automatically expand to the limits of the groove in a direction parallel to the longitudinal axis of the piston. lt is appreciated, of course, that some action must take place in a plane at right angles to the longitudinal axis of the piston, where the two parts are moved in the direction described, but instead of wedging the outer part of the ring firmly against the inner face of the cylinder, the increase of pressure onthis. member is almost negligible; on the other hand, the innermost part of the ring is moved inwardly more deeply into the piston groove.

llllh Reference is had to the accompanying drawings as illustrating one practical embodiment of my invention, and in which- Figure 1 is a side elevation of one form of :ring, the same being applied to what is known as a tight groove;

Fig. 2 is a sectional view taken along the lines 2-2 of Fig. 1;

Fig. 3 is a view illustrating a device identical with the ring illustrated in Fig. 1, but in which such ring is applied to what is knownas a hammered groove;

Fig. 4 is a sectional view taken along the lines 4'4 of Fig. 3; 4

Fig. '5 is another form ofring applied also to dwhat is known as a hammered groove; an

Fig. 6 is a section taken along the lines 6-6 of Fig. 5.

In these figures the reference numeral 1 indicates av cylinder in which is slidably mounted in the conventional manner a piston 2 The piston is, of course, provided with a conventional groove, or grooves. Mounted in thls groove ismy improved r1ng,wh1ch mcludes an inner member 3, preferably constructed of spring steel, and an outer mem her 4 which may be of iron. To obtain the action specified in the preamble to this specification, I form the inner ring '3, as aforestated, of spring steel, which will tend to force the outer annular bands 4 firmly into engagement with the inner face of the cylinder 1. As it will be noted, the inner part or band 3 comprises an outer face 5 which, in all of the various views, includes two inclined faces 6 and 7 meeting approximately centrally of the inner band 3. In-

the device illustrated in Figs. 2 and 4, I provide the inner band 3 with ashoulder 8,

which shoulder extends from a point adjacent the end of the inclined face 7 up 'wardly and terminates in a plane approximately in line with piston 2. e

The outer band 4 has its inner face formed, or grooved, so as to correspond to the outer face of theinner band 3 upon which it seats. It will be noted, however,

the outer face of the that the face 9 formed upon itsunder side is considerably shorter than the face 7 ,formed upon the upper side of the inner band 3, while the face 10 is longer than the face 6.

Now, in operation it will be noted that normally the outer band will be incapable of coming unseated from the inner band, in

view of the interlocking relationship between the upper face of the inner band and theunder face of the upper band. Further, the normal tendency of the two parts of this ring will be for the inner and outer members to slide even beyond the position in which they are illustrated in Fig. 4, so that the face 9 may lie flush with the face 7,

leaving a space 11 between the inner band and front part of the groove, as well as a space between the side face of the outer ring 4 and the side face of the shoulder 8, as indicated at 12. However, it will be perfectly obvious that it would be impracticable to seat a ring in which the parts had moved parallel to the longitudinal axis of the piston to a position beyond that indicated in Fig. 4 in the groove; and it would, hence, prove advisable to use a piston ring which would be anywhere up to one six. teenth of an inch, for example, wider, so that the ring after having been applied to the groove might seat in the same in the manner indicated in Fig. 2, in which the engagement of the side faces of both the inner and outer rings has pressed these two members together and has caused the -face 10to ride upwardly upon the face 6, resulting in spaces 11 and 12 being filled in, and also in the forming of a new space between the rings, as indicated at 13. As it will have been noted, the action of pressing the inner and outer members 3 and 4 together parallel to the longitudinal axis of the piston does not result in the outer ring 4 binding against the inner face of the piston; but, as it will be noted from an examination of Figs. 2 and 4, the inner spring band 3,'although con-..

siderably spaced from the base of the groove, as indicated by the reference numeral 14 in Fig. 4, is .pressed downwardly until the same almost seats against the base of the roove, as indicated in Fig. 2, it being un erstood, however, that it would not prove practical to have the underside of the inner ring 3 engaging the base of the groove, for obvious reasons.

Referring now to the device illustrated in Figs. 5 and 6, it is pointed out that this construction is similar in every respect to the device as illustrated in Figs. 1, 2, 3 and 4, with the exception that the outwardly-extending shoulder 8, of the inner ring 3, is eliminated.

This construction, although possibly not embodying quite as good a combination as incorporated in the construction illustrated in Figs. 2 and 4, combines apiston ring which shall have practically the same operation as thedevice illustrated in the aforementioned figures, with the exception that the device illustrated in this latter figure may be manufactured far more cheaply than the afore-described modifications.

It is to be distinctly understood, however, that in all these views, no matter what stroke the engine is upon, the ring is seating bodily against both side edges of the piston ring groove, and that should a ring be taken from out of a groove which has been hammered, and is, consequently, widened, and laced in a tight groove, the same will readily adapt itself to this latter groove by simply conweasel stricting the inner band, but by increasing the outward pressure of the outer hand against the inner face of the cylinder Wall to an unappreciable extent only, whereby no grinding action between the outer face of the piston ring and the cylinder Wall will result.

It is to be understood that in all of the views illustrated in the accompanying drawings, the combustion chamber is adapted to be located below the ring.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

A piston ringjcomprising an inner ring member and an outer ring member, said members being associated in interlocked relation and susceptible as a unit of longitudinal and peripheral expansion, the outer face of the inner member including a central outwardly extending angular ridge, oppositely inclined face portions diverging from said ridge, and ashoulder projecting outwardly therefrom at the termination of one of said inclined face portion s, the inner and outer faces of the shoulder being parallel and the peripheral face of the shoulder normally flush or slightly within the periphery of the piston the inner face of the outer ring member comprising an angular groove formed of oppositely inclined continuous plane surfaces extending from the angle of the groove and terminating in the inner edges of the upper and lower faces of the member, one of said plane surfaces being complementary to the reversely inclined face of the inner ring member and having a free sliding contact therewith," whereby axial and radial movements may be imparted to the ring elements to seal the opposite sides of the piston groove.

THOMAS GUNNI SAXTON. 

